Automobile interior parts (for example, roof linings, door trims, instrumental panels, dash silencers, center consoles, pillars, ornaments, rear parcels, and sheet covers) are generally obtained by adhering a cover material made of a polyolefin or a decorating material such as a fabric to a molded article made of a polyolefin such as polypropylene or polyethylene with an adhesive by a vacuum molding method, a pressure bonding method using a press, or the like. Chloroprene adhesives have hitherto been used for the adhesion. It is desired, however, to replace the chloroprene adhesives with adhesives containing no halogen, from the viewpoint of environmental safety.
As an alternative to the chloroprene adhesive, there are adhesives containing a styrene copolymer as a base polymer, but they are not suitable for use in adhering automobile interior parts because of their low heat resistance. In order to improve their heat resistance, silane-modification of a styrene copolymer has been performed (Patent Documents 1 and 2), but these adhesives do not have sufficient heat-resistant adhesion to polyolefins. In addition, when an olefin bonding agent is added thereto in order to improve the heat-resistant adhesion, there arises a problem of phase separation.
Patent Document 1: JP-A-2000-303047
Patent Document 2: JP-A-06-33027